I found another relevant article. I'm a bit skeptical about Neanderthals having advanced mathematical intelligence, but I'd like to hear everyone's thoughts on that. (I thought that mathematical ability was more of a melon thing.)

"As researchers Lee Jantz, coordinator of Forensic Anthropology Center, Richard Jantz, professor emeritus, and Joanne Devlin, adjunct assistant professor, catalogued 1,500 noggins they observed that white people who were born in the 20th century had bigger heads.
They looked at white skulls because they wanted to have a large sample and they don’t have as many black and Hispanic skulls. When people decide to donate their bodies to science, some of those bodies end up at the Forensic Anthropology Center. Historically, more white people have donated their bodies to science than black or Hispanic people, but Jantz suspects that as the makeup of America changes, the center will receive more donations from black and Hispanic people.
The height of white male skulls has increased by eight millimeters and the overall skull has grown by 200 cubic centimeters. For women, cranium height increased by seven millimeters and overall by 180 cubic centimeters.
“The basic thing that we observed over the course of looking at crania that belong to people born from 1820s to 1980s, is that the cranium has gotten higher and narrower,” says Richard Jantz, who is married to Lee.
“If you just look at a side view of the skull, what you would see is the distance from top to bottom increased, and if you look at a front view of the skull, you would see the distance from side to side decreased.”"[H/t aeoli]

Who decides to donate his body to "science" ? Probably materialistic people working in scientific, especially medical, fields. Those professions have dramatically increased in number, and the requirements have changed and become far more school-like, repetitive, formalized. This might be one reason for this change.

"A study of 90 ice-hockey players found that a wider face in which the cheekbone-to-cheekbone distance was unusually large relative to the distance between brow and upper lip was linked in a statistically significant way with the number of penalty minutes a player was given for violent acts including slashing, elbowing, checking from behind and fighting." [from wiki]